EP0169488A2 - Circuit transformateur - Google Patents

Circuit transformateur Download PDF

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Publication number
EP0169488A2
EP0169488A2 EP85108921A EP85108921A EP0169488A2 EP 0169488 A2 EP0169488 A2 EP 0169488A2 EP 85108921 A EP85108921 A EP 85108921A EP 85108921 A EP85108921 A EP 85108921A EP 0169488 A2 EP0169488 A2 EP 0169488A2
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EP
European Patent Office
Prior art keywords
voltage
winding
switch
switching state
switches
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85108921A
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German (de)
English (en)
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EP0169488B1 (fr
EP0169488A3 (en
Inventor
Walter Dr. Dipl.-Ing. Mehnert
Ludwig Dr. Dipl.-Ing. Bölkow
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Voigt and Haeffner GmbH
Original Assignee
MITEC MODERNE INDUSTRIETECHNIK GmbH
Voigt and Haeffner GmbH
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Priority claimed from DE19853502889 external-priority patent/DE3502889A1/de
Priority claimed from DE19853511182 external-priority patent/DE3511182A1/de
Application filed by MITEC MODERNE INDUSTRIETECHNIK GmbH, Voigt and Haeffner GmbH filed Critical MITEC MODERNE INDUSTRIETECHNIK GmbH
Priority to AT85108921T priority Critical patent/ATE68611T1/de
Publication of EP0169488A2 publication Critical patent/EP0169488A2/fr
Publication of EP0169488A3 publication Critical patent/EP0169488A3/de
Application granted granted Critical
Publication of EP0169488B1 publication Critical patent/EP0169488B1/fr
Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current 
    • G05F1/12—Regulating voltage or current  wherein the variable actually regulated by the final control device is AC
    • G05F1/24—Regulating voltage or current  wherein the variable actually regulated by the final control device is AC using bucking or boosting transformers as final control devices
    • G05F1/26—Regulating voltage or current  wherein the variable actually regulated by the final control device is AC using bucking or boosting transformers as final control devices combined with discharge tubes or semiconductor devices
    • G05F1/30—Regulating voltage or current  wherein the variable actually regulated by the final control device is AC using bucking or boosting transformers as final control devices combined with discharge tubes or semiconductor devices semiconductor devices only

Definitions

  • the invention relates to a transformer circuit according to the preamble of claim 1.
  • Such transformer circuits are used, with the aid of at least one actuating unit, which can be brought into different switching states, to change the amplitude of an AC supply voltage emitted by a voltage source, if necessary, before it is applied as a load AC voltage to a consumer.
  • Such a transformer circuit is known for example from DE-OS 25 00 065.
  • This circuit comprises a single control unit with a transformer, the primary winding of which is fed by the supply voltage emitted by the voltage source.
  • Several taps are provided on the secondary winding, which can be optionally connected to the lines leading to the load by means of automatically controllable switches. This ensures that the same AC voltage amplitude is always supplied to the load even when the circuit is connected to voltage sources which emit different AC voltages with respect to the amplitude.
  • the invention has for its object to provide a transformer circuit of the type mentioned, with the help of which the amplitude of the supply voltage emitted by the voltage source can be changed in a simple and quick manner and with extremely low energy losses.
  • the invention provides the features set out in claim 1.
  • the main part of the power of the load is supplied via the first winding of the transformer in a galvanic way, whereby due to the low number of turns of this winding and low frequencies with which high powers are delivered to loads, the inductance of this first winding produces only a very small voltage drop with correspondingly small losses, which moreover occur in an increased manner in the case of conventional transformer circuits.
  • the at least one control unit of the transformer circuit can be brought into at least one switching state by applying a control voltage U s to the further winding, in which a voltage .DELTA.U 1 is induced in the first winding of the transformer additional winding with respect to the first winding added to or subtracted from the input voltage, so that the following applies to the output voltage U A, which is different from the input voltage:
  • the turn ratio w 1 / w w is here substantially less than 1 and is preferably in the range from 1: 7 to 1: 200.
  • the current that flows through the further winding in the first switching state is to be matched to the nominal load current that flows through the first winding of the transformer so that, for a given turns ratio, the fluxes of both windings are approximately the same in amount and such an angular displacement mutually sen that the magnetic flux, which results in the transformer core, leads to the desired induced additive or subtractive voltage drop ⁇ U 1 at the first winding of the transformer. It can be seen that under these conditions the induced voltage drop ⁇ U 1 is largely independent of the load current, so that a constant difference between the input and output voltage of the actuator can be maintained even if the load current fluctuates in relation to its nominal value.
  • a major advantage of this arrangement is that the magnetic coupling of the transformer is only the small part of the power that is required for the induced change in amplitude. This significantly reduces the energy losses caused by the inductive energy transfer from one transformer winding to the other.
  • the transformer can thus be dimensioned correspondingly smaller and the effort required for cooling the transformer can be reduced.
  • the switches which can be used to apply the control voltage to the further winding of the transformer, also result in only a small part of the total power, so that the switches are loaded far less even with frequent switching operations.
  • semiconductor switches e.g. Triacs or switches constructed from V-MOS transistors are used which enable switching to be carried out considerably faster than the mechanical switches used in such cases according to the prior art.
  • a complete interruption of the energy supply to the load during switching cannot occur in principle, since the galvanic connection between the load and the voltage source is constantly maintained via the first winding of the transformer.
  • the switching state in which such an actuating unit is located when the first control voltage U S1 is applied is referred to as the first switching state, which is determined by the above Equations (1) and (2) are described, so when the second control voltage U S2 is applied to the further winding under the same conditions as above, a second switching state results, in which a defined second voltage drop AU2 at the first, largely independent of the load current Winding is induced.
  • the output voltage U A the following applies to the output voltage U A :
  • ⁇ U 2 depends on the control voltage U S2 also according to equation (2) above.
  • the control voltages used are preferably the input voltage U E and the output voltage U A of the actuating unit, to which the further winding is galvanically connected with the aid of the switch, taking into account the sense of the winding, in such a way that the induced voltage ⁇ U 1 is added to the input voltage and the other induced voltage ⁇ U 2 subtracted from the input voltage U E.
  • these two inducible voltages ⁇ U 1 and ⁇ U 2 cannot be selected independently of one another. Rather, they are according to the equations and linked to one another if w 1 is the number of turns of the first winding and w is the number of turns of the further winding of the transformer.
  • the control unit can be brought into a third switching state in which no voltage is induced in the first winding of the transformer. So that the first winding does not develop a throttle effect with a correspondingly high voltage drop in this third switching state, care must be taken that the magnetization of the transformer core is not essentially caused by the flooding of the first winding alone. This can be done in various ways, as will be explained in more detail below. It is essential that in this third switching state only an extremely low voltage drops at the first winding of the transformer, so that with a good approximation the output voltage of the actuating unit is equal to the input voltage:
  • a first possibility for realizing the third switching state is to provide a switch, with the aid of which a further winding can be short-circuited, whereby it is disconnected from all control voltages at the same time.
  • each switch In order to make a simultaneous closing of these switches impossible, the switching state of each switch is monitored with the aid of an associated sensor unit and a closing command for a previously open switch is suppressed by a blocking circuit if the output signal of the sensor unit of the other switches indicates that one of these other switches is still closed.
  • the output voltage U A of the actuating unit changes as quickly and as “smoothly" as possible, ie without strong fluctuations in the absolute amplitude of the output AC voltage up or down from its old to the new amplitude value.
  • the currents that flow in the two antiparallel windings each try to build up a magnetic field in the core of the transformer; however, these fields face each other and essentially cancel each other out.
  • the leakage inductance and the ohmic resistance of the first winding through which the load current flows are very small.
  • the voltage drop occurring at it is therefore very small and the above equation (8) applies with a good approximation.
  • the current flowing through the further winding is correspondingly small, since the further winding has a significantly higher impedance than the first winding of the transformer. As a result, the load current flows practically exclusively through this first winding.
  • the third and fourth switches i.e. the two switches with which the two ends of the further winding can be connected to the connecting connecting conductor of the actuating unit, for example themselves each be designed as a current limiting circuit in such a way that they do not let any current through at all in the open state and the current flowing through them in the closed state only oppose a very small, constant resistance as long as this current remains below a predetermined limit value, but prevent the current from rising above this limit value.
  • the transition from the first to the second switching state or from the second to the first switching state then takes place simply in such a way that the two switches opened in the previous switching state are also closed, which corresponds to a transition to the third switching state, and only then do the switches opened, which must be open in the new switching state. Because of their current limiting properties, the third and fourth switches prevent impermissibly high short-circuit currents from flowing in the third switching state.
  • the third and fourth switches ie the two switches with which the two ends of the further winding can be connected to the connecting connecting conductor of the actuating unit, do not lead directly to this connecting connecting conductor.
  • the third and fourth switches are directly electrically connected to one another by a further conductor and a circuit arrangement is provided between this further conductor and the connecting connecting conductor, which on the one hand connects the two conductors in an electrically conductive manner and on the other hand the flow of an impermissibly large current of one of these two conductors prevented on the other.
  • this circuit arrangement can be a switch which is always opened when the actuating unit is to be brought into its third switching state, in which an impermissibly high short-circuit current would otherwise flow via this switch.
  • switches can only be opened at very specific times, so that the optimum switching speed cannot yet be achieved with them.
  • an automatically operating current limiting circuit is preferably used as the circuit arrangement, which opposes the current flowing through it with only a very small, constant resistance, as long as this current is less than a predetermined limit value.
  • the current limiting circuit steadily increases its resistance so that the current cannot exceed the predetermined limit.
  • this continuous limiting process has the advantage that there are no voltage peaks in the output voltage of the actuator.
  • the limit value is chosen so that it is only slightly greater than the current which must flow through the further winding in the first or second switching state and also through the current limiting circuit lying in series with the further winding in these two switching states.
  • the transition from the first to the second switching state is preferably carried out here in such a way that first the second switch is closed, which connects the second end of the further winding to the output end of the first winding. Since in the first switching state the first switch is closed, which connects the first end of the further winding with the input-side end of the first winding, and since this first switch initially remains closed, the two windings are temporarily electrically parallel to one another and the actuating unit is located in the third switching state.
  • the current limiting circuit prevents an inadmissibly high short-circuit current from flowing through the closed second switch and the fourth switch, which is also still closed and which connects the second end of the further winding to the further conductor and thus also to the connecting connecting conductor.
  • the switching process is then continued in such a way that the fourth switch is opened and then the third switch is closed, which connects the first end of the further winding to the further conductor. Even with this switch position, the actuating unit is in the third switching state, since the first and the second switch are still closed. An impermissibly high short-circuit current could now flow through the first and third switches, but this is prevented again by the current limiting circuit. Finally, the first switch is then opened so that the actuating unit changes to the second switching state.
  • the current limiting circuit can advantageously be designed in such a way that it can be switched to at least one second current limiting value, which is substantially lower than the first current limiting value, preferably equal to zero. In this way, the further winding lying parallel to the first winding of the transformer is practically completely separated from the input voltage U E and there is no longer any short-circuit current at the connecting connecting conductor.
  • An automatically operating current limiting circuit has the advantage over a switch, in addition to the already mentioned avoidance of switching peaks, that it prevents the current flowing through it from exceeding the predetermined limit value without any delay.
  • the limit value to which the current limiting circuit limits the current flowing through it not only to and fro between two values switched but can be changed continuously in a predetermined range. This makes it possible, on the one hand, to limit the short-circuit current flowing in the third switching state to an uncritical value and, on the other hand, to control or regulate, if necessary, the currents flowing through the relevant further winding in the first or second switching state.
  • an actuating unit comprises a transformer with a single further winding and four switches, of which the first and second are designed as triac and the third and fourth as current limiting circuits, then when switching from the first (second) to the second (first) switching state the to switches open at the start of switching, ie the second (first) and third (fourth) switch are closed immediately and without any delay, as a result of which the actuating unit changes to the third switching state. To get from this into the second (first) switching state, the first (second) and fourth (third) switch must be opened. Since it is assumed here that the first (second) switch is a triac, this is only possible if it is and the short-circuit current flowing through the winding has a zero crossing.
  • control unit not only briefly passes through the third switching state during the transition from the first to the second or from the second to the first switching state, but has also been in the third switching state for a long time and is brought into the first or second switching state by the latter should.
  • the third (fourth) switch can then be closed with a certain time safety margin and only then is it possible to open the first (second) switch, for which a zero current crossing must again be waited for.
  • a waiting time of two half-periods can result in the worst case. If the actuator is held in the third switching state for a long time, the third and fourth switches can be opened. If a transition to the first (or second) switching state is then to take place, the fourth (third) switch must first be closed, which can happen at any time; then the second (first) switch is opened, for which a zero current crossing must again be waited for.
  • the invention provides instead of using triacs electronic switches which can not only be closed at any time but also opened again.
  • V-MOS transistors are available, of which two each have to be connected in series with their source-drain paths with opposite polarity in order to set up an AC voltage switch. With these switches, there are no waiting times until the next zero current crossing.
  • a switching criterion that is independent of the zero crossing of the short-circuit current can be used for the opening processes, which each lead from the third switching state to the first or second switching state, which leads to the smallest possible change in the current in the further winding lying on its control voltage after the switching process .
  • the output voltage of the actuating unit has exactly the new amplitude value without voltage peaks or voltage dips.
  • a fourth switching state can be produced for an actuating unit, the transformer of which has only a single further winding, in that the switches of the actuating unit are actuated in such a way that the circuit of the further winding has a high resistance value, which, even after being transformed down, on the side of the first Winding provides a high resistance value.
  • the entire magnetization of the transformer core is caused by the flooding of the first winding.
  • a voltage drop dependent on the size of this flow and thus on the size of the load current then occurs at the first winding.
  • This throttling effect of the first winding in the fourth switching state can be used to limit the power supplied to the load to a safe level when a short circuit occurs at the load.
  • the transformer can also have two further windings, the flooding and winding conditions for the first winding meet the same conditions as those specified above for the further winding.
  • the actuating unit is brought into the first switching state in that a control voltage is only applied to the first further winding; in the second switching state
  • the actuating unit is brought about in that a control voltage is applied only to the second further winding.
  • the number of turns, the control voltages and the sense of winding of the two further windings with respect to the first winding are chosen so that the amplitudes of the two inducible voltages ⁇ U 1 and ⁇ U 2 are approximately the same size, but the two inducible voltages have opposite signs on the Input voltage U E can be impressed.
  • the two equations (4) and (5) above again apply to the first and second switching states.
  • the control voltages can indeed be generated in various ways and applied to the further windings.
  • the first further winding is preferably directly galvanically connected to the input voltage U E of the actuating unit with the aid of the switches, while in the second switching state the second further winding is directly galvanically connected to the output voltage U A of the actuating unit, so that in both Switching states receives an autotransformer arrangement.
  • One of the two further windings is used exclusively as an adding winding and the other is used exclusively as a subtracting winding.
  • an additive induced voltage + ⁇ U 1 and a subtractive induced voltage -AU2 are also available.
  • this embodiment allows one end of each of the two further windings to be firmly connected and only the other end to be either electrically conductively connected to the input or output voltage or separated from it with the aid of a switch. So fewer switches are needed.
  • Such a transformer circuit is particularly advantageous if the voltages to be induced + ⁇ U 1 and - ⁇ U 2 make up only a comparatively small percentage of the input voltage U E.
  • the bond ratios w 1 / w w b between w 1 / w w1 and w1 / ww2 are therefore generally less than 1 and are preferably in a range from 1: 3 to 1: 200.
  • This second embodiment can also be constructed in different variants, which produce a enable third switching state, in which the output voltage of the actuating unit is practically the same as the input voltage, in different ways.
  • a first possibility is that switches are provided, by means of which the two further windings can each be short-circuited.
  • special measures must be taken to avoid overloading the transformer, which ensure that the switch or switches used to apply a control voltage are closed only for one of the two further windings.
  • each switch is also monitored here with the aid of an associated sensor unit and a closing command for a previously open switch is suppressed by a blocking circuit if the output signal of the sensor unit of the other switches indicates that one this other switch is still closed.
  • a transformer which has two further windings, each of which is connected at one of its two ends to the front or rear end of the first winding as seen from the voltage source, one is provided in order to achieve the third switching state these two further windings are connected in series with the first winding in parallel; these two further windings lying in series with one another can be regarded as a single winding which has a continuous winding direction.
  • a short-circuited transformer is again obtained with two windings wound antiparallel on the core and connected to the same voltage.
  • the currents in these antiparallel windings try to build up opposing magnetic fields in the core of the transformer, which essentially cancel each other out.
  • the above equation (8) applies again.
  • the current flowing through the two further windings lying in series with one another is very small, since these further windings have a significantly higher impedance than the first winding.
  • the load current therefore flows almost exclusively through the first winding.
  • the two switches with which the two free ends of the two further windings can be connected to the connection connecting conductor, are likewise connected directly to one another in a galvanically conductive manner by a further conductor, and there is a circuit arrangement between the further conductor and the connecting connecting conductor Provided above under A) type, which is preferably again formed as a current limiting circuit.
  • the previously open switch is first closed during the transition from the first to the second switching state or from the second to the first switching state, as a result of which the actuating unit temporarily changes to the third switching state; the current limiting circuit in turn prevents the flow of an impermissibly high short-circuit current.
  • the switch which was closed in the previous switching state is opened, as a result of which the control unit changes to the new switching state.
  • triacs which, for example, each consist of a series connection of two V-MOS transistors and can be closed and opened at any time.
  • the waiting times until the next current zero crossing no longer apply and the switching criterion described above, which is independent of the zero crossing of the short-circuit current, can be used if a switch has to be opened to transition from the third switching state to the first or second switching state.
  • a point in time is used as the switching time at which the current which flows through the further winding connected to its control voltage after the switching process has its zero crossing. Since a different current flows through the two further windings in the third switching state than when the corresponding further winding is connected to its control voltage in the new switching state, the time interval between the zero crossing of the last-mentioned current and the zero crossing of the input AC voltage is also in a previous one Period measured and the measured value saved. With the help of this stored value, the above-mentioned favorable switching time can then be determined again.
  • the time periods required for the switching processes can also be made extremely short. If the actuating unit is in the first or in the second switching state and a switchover to the second or first switching state is necessary, it can be switched off in the case of V-MOS transistors permitted embodiments carry out the first half of the change occurring in the output voltage immediately at any time and the second half of this change within a half period of the AC voltage to be switched.
  • the transformer can indeed have several further windings, each of which can have different numbers of turns. These number of turns can be within the above-mentioned range from 1: 3 to 1: 200, but should only differ from each other to such an extent that if the associated voltage is applied to the further winding with the smallest number of turns, none in the other further windings excessive voltages are induced.
  • a corresponding number of switches can be provided, with the aid of which each of these windings can be connected to or disconnected from a control voltage. It is also possible to apply a control voltage to only one or to two or more of the further windings at the same time.
  • a preferred possibility, according to the invention, of optionally providing more than three different output voltages in succession at the output of a single actuating unit, is alternatively one of a plurality of control voltages U S1 , ..., to the at least one further winding with the aid of switches.
  • US2q anz place u-, which differ at least partially in amplitude from each other.
  • Q is any integer greater than 1.
  • an AC voltage source is preferably used which has a plurality of taps, between which different tap voltages U X1 , ..., U XP are constantly available and can be tapped off.
  • p is also an integer greater than 1 and preferably less than q.
  • the change range can only be positive or only negative; ie only the additive or only the subtractive impression of induced voltages AU on the input or supply voltage may be required.
  • the general case of a change range ⁇ ⁇ U max that is symmetrical to the change zero (input voltage equals output voltage) is explained.
  • any voltage that can be impressed + ⁇ U 2 is an integer multiple of the associated smallest voltage that can be impressed + ⁇ Umin and that 2 can assume all integers between 1 and q.
  • the greatest possible inducible voltage in each direction is also the limit of the range of change:
  • the range of change can be varied both by choosing the smallest change ⁇ ⁇ U min and thus the step size, and by choosing the number q of cuts.
  • an increase in the step size leads to a reduction in the accuracy with which the load voltage U L can be kept constant at a predetermined value, for example when using the transformer circuit according to the invention.
  • an increase in q means an increase in the technical outlay.
  • the amplitudes of + ⁇ U min and - ⁇ U min are preferably at least approximately the same size, so that the following also applies at least approximately to the other inducible voltages:
  • control voltages U S ⁇ to be applied to the further winding are digitally structured in accordance with the invention, ie there is a smallest control voltage U Smin which leads to the impressing of the smallest induced voltage ⁇ U min , and the other control voltages are integral multiples of this smallest control voltage :
  • the amplitudes of the tap voltages are graded according to a suitable code so that, with a minimum number of taps (and thus also a minimum number of switches), all required control voltages U S ⁇ can be combined by additively combining several tap voltages, unless they are directly one of the voltages correspond to that between two be neighboring taps are available.
  • the smallest control voltage U Smin is available, at least one pair must., Hen be provided for by adjacent taps between which U Xmin U Smin falls from a voltage riffs g. Between the other pairs of adjacent taps, tap voltages can then be at least partially provided, which, according to the code mentioned above, are integer multiples of the smallest tap voltage U Xmin different from 1.
  • the cheapest code here is the pure binary code, in which each tap voltage occurs only once, and the tap voltages 1 in succession between successive tap pairs.
  • U Xmin etc. fall off.
  • alternating voltage source consisting of an additional transformer arrangement having a winding consists, to which an alternating voltage is applied and which is divided into a plurality of winding sections, btell between which the taps to the A of the Abgriffsspannun g en U X1, ... , U XP are brought out
  • a code is preferably used here which allows any control voltage required to be tapped from a group of taps which follow one another immediately, unless it can be tapped directly from a single tapping pair.
  • the number of turns of the winding sections is preferably selected such that the tap voltage 1 at the section lying at one of the two ends of the row of winding sections.
  • U Xmin can be tapped directly, as is the case with the first of the two examples above.
  • the code is always selected so that all the required control voltages U S2 are available with a minimum number of winding sections or taps.
  • the maximum alternating voltage that can be tapped across the combination of all winding sections should be the same or at least not significantly greater than the maximum required control voltage U Smax .
  • the additional transformer arrangement preferably consists of only a single winding which is divided into the different sections and at the extreme ends of which a corresponding AC voltage is applied.
  • the input or output voltage of the actuating unit itself can be used.
  • the invention further provides that the voltage applied to the load Voltage U L is measured with the aid of a sensor arrangement that a comparator receives the output signal compares the sensor arrangement with a reference value U ref , which represents the nominal value S of the load voltage, and that a switch control is provided which controls the switches on the basis of the difference signal emitted by the comparator arrangement in such a way that those induced in the first winding of the transformer Counteract changes in voltage ⁇ U ⁇ of any fluctuations in the load voltage U L and compensate for these fluctuations.
  • the stages connected in series with one another can each consist of a single actuating unit which is designed with one or more, in particular two further windings, and according to one of the embodiments described above, at least into the equations (4), (5) and ( 8) defined three different switching states can be brought.
  • stages of such a transformer circuit can also each consist of two actuating units connected in series, which are combined to form a pair of actuating units.
  • each of the two actuating units which also have two further windings, one of which is used as an additive and the other as a subtracting winding.
  • the two transformers are dimensioned in such a way that each of the two actuating units, both in an adding and in a subtracting manner, is able to effect approximately half of the total voltage change that is to be applied by the actuating pair. For example, if the pair of actuating units should be able to change its input voltage U EP by + ⁇ U P , then each of the two actuating units can change the input voltage of + ⁇ Up / 2 supplied to it on its own. If each of the two actuating units is in its first switching state, this is referred to as the first switching state combination of the actuating unit pair and it applies to the output voltage of the actuating unit pair when U EP is the input voltage of the actuator pair.
  • the turn ratios of the two transformers are matched to one another in such a way that the effects of the two actuating units compensate one another when the actuating unit pair is in a third switching state combination;
  • this third switching state combination for example, the first actuating unit closer to the supply voltage source is in the first and the second actuating unit in the second switching state. It then applies to the output voltage of the actuator pair
  • the fourth switching state combination remains unused for a pair of actuating units, in which the first actuating unit is in the second switching state and the second actuating unit is in the first switching state.
  • each of the two control units of the control unit pair can be brought into the third switching state on its own.
  • each of the two actuating units is preferably designed such that the one further winding or both further windings can be connected in parallel with the first winding, ie each of the two actuating units can be brought into the third switching state on its own; one sees the current limiting circuit or current limiting circuits mentioned above in each setting unit Before, V-MOS transistor switches can be used to carry out an extraordinarily fast, multi-step switching from each switching state combination of the actuating unit pair to any other switching state combination.
  • the third switching state combination has the advantage over the other switching state combination that, if necessary, a transition to the first or the second switching state combination can take place in two equally large change steps, the first of which can be carried out without any delay, that the second or the first actuating unit is brought into its third switching state by closing the switch in question.
  • the transition from the first to the second or from the second to the first switching state combination likewise takes place in two steps, of which the first can be carried out immediately and the second at the latest within the next half cycle of the AC voltage.
  • the first step consists in bringing both actuating units into their third switching state simultaneously by closing the corresponding switches; in the second step, the the control units are converted into their second or first switching state by opening the corresponding switches.
  • transformer circuit consisting of one or more such pairs of actuating units (which can then cause different voltage changes) is used as a voltage regulator or voltage constant, it can also be used to meet the extremely high requirements in terms of switching speed and switching accuracy, such as those used in the Power supply of data processing systems are provided.
  • a "+” means that one or both actuating units of a pair are in the first switching state in the relevant stage, so that the amplitude of the supply voltage is increased by 9A%, 3A% or A% while a "-" means a corresponding reduction and "O” symbolizes the third switching state of an individual control unit or the switching state combination 3 (see Table 1) of the relevant control unit pair, in which or in which the amplitude of the input AC voltage is passed on unchanged becomes.
  • the right column shows the total changes in amplitude that can be achieved by the respective combination of the switching states of all stages. Only rounded values are given, which do not take into account that the input voltage of the stages closer to the load can change depending on the switching state of the preceding stages.
  • a stage is made up of two actuating units that form a pair, as an alternative to the arrangement just explained, only two switching state pairs can be used for each actuating unit pair.
  • Combinations are used, for example the switching state combination O, in which the output voltage is equal to the input voltage, and the combination “-”, in which the output voltage is n.
  • control unit pairs can also be provided, which can only assume the two switching state combinations O and + n ⁇ A%.
  • transformer circuit according to the invention consisting of two, three or more stages does not consist in the fact that nine, twenty-seven or more output voltages should be able to be generated one after the other starting from a fixed supply voltage originating from a voltage source.
  • a circuit arrangement comprises, in addition to a transformer circuit with a corresponding number of stages, a sensor arrangement which measures the amplitude of the supply voltage and / or the amplitude of the load voltage, a comparator arrangement which compares the sensor signal or signals with one or more reference values and, in the event of deviations, corresponding difference signals generates, as well as a switch control that compares these difference signals, for example, with a permanently programmed table of difference signal values. From this comparison, the switch control determines the combination n or n of switching states (see Table 2) that is required to compensate for the deviation of the supply voltage from the nominal value, so that the load voltage remains within the specified range S L f%.
  • a corresponding integer multiple of A% is subtracted from the supply voltage and the load voltage is thus kept in the desired range S L ⁇ ⁇ %.
  • the transition from the nth combination to the (n + 1) - th combination takes place at a certain switching threshold SW n - / (n + 1) - that is to say a fixed amplitude value of the supply voltage. If the positive deviation steadily decreases again, the transition from the (n + 1) th combination to the n th combination of switching states takes place at the same switching threshold in the opposite direction. It is advantageous to separate the last two switching thresholds from one another by means of a small voltage difference. The "hysteresis" achieved in this way prevents an excessive switching cycle in cases in which the supply voltage U V has a value for a long time which is equal to a switching threshold and fluctuates slightly around this value.
  • the switching thresholds are preferably set such that when the amplitude of the supply voltage passes the value of the switching threshold in question without a sudden change, the amplitude values U Lvor and U Lnach are symmetrical to the setpoint. It is U Lvor the amplitude of the load voltage before the U mschalt- process and U L after the amplitude of the load voltage by the switching operation. The following should therefore apply with the best possible approximation:
  • A ⁇ S. 100.
  • the percentage value A is constant, but is not related to the target value S L but to the amplitude of the input voltage of the respective stage. The size of U Lvor and U Lnach therefore depends on which combination of switching states a transition to an adjacent combination takes place.
  • A should be as large as possible, so that as few actuators as possible are required to cover a given fluctuation range ⁇ , but on the other hand A should not be chosen too large, because otherwise the desired control accuracy J is not can be observed.
  • A is preferably chosen so that it is between 1.6 ⁇ and 1.8 ⁇ .
  • the switching thresholds can be used regardless of whether the circuit arrangement works as a voltage constant or as a voltage regulator, i.e. whether the load voltage U L is kept at a setpoint value S L which is equal to the nominal value of the supply voltage emitted by the voltage source or at a target value that differs from this nominal value.
  • switching thresholds are also independent of whether the supply voltage or the load voltage is measured with the sensor arrangement.
  • the difference between the above switching thresholds and the desired value S L can be contained directly in the table used by the switch control, with which the difference signal supplied by the comparator is compared.
  • the switch control In the second case, the switch control must determine from the approximation of the amplitude of the load voltage to one of the values U Lvor and U Lnach and / or knowledge of the currently valid combination of switching states, to which switching threshold the supply voltage is approaching and which switchover must therefore be carried out .
  • the sensor arrangement measures the amplitude of the alternating voltages in front of and behind the transformer circuit.
  • the changes in both the supply voltage Uv and the load voltage U L are then detected and evaluated in such a way that the switches of the actuating units are controlled in such a way that the amplitude of the voltage supplied to the load is as constant as possible.
  • a transformer circuit according to the invention can advantageously be used in multiphase systems with or without a neutral conductor.
  • at least one control unit is provided for each phase, the first winding of which lies in the respective phase conductor in such a way that the load current flowing on this phase conductor flows through it, while the connecting connecting conductor of each control unit with the neutral conductor of the multiphase system connected is.
  • the multiphase system does not have a neutral conductor leading from the voltage source to consumption, the first windings of the actuating units which are provided for a specific phase are switched back into the phase conductor and all the connecting connecting conductors are connected to one another, thereby creating an artificial zero -Conductor is formed, which can be at any potential.
  • the actuating units provided for the different phases can be arranged in a daisy chain.
  • FIG. 1 shows an AC voltage source 1, which emits a supply voltage U v , which is fed to the input connections 2, 3 of an actuating unit 4 as an input voltage U E.
  • An output voltage U A appears at the output connections 5, 6 of the actuating unit 4 and is supplied to a load 7 as a load voltage U L.
  • the control unit 4 comprises a transformer 8, the first winding 9 of which is connected between the input connection 2 and the output connection 5, while the input connection 3 is connected directly to the output connection 6 by means of the connection connecting conductor 10. In this way, seen from the voltage source 1, the first winding 9 is connected in series with the load 7.
  • the transformer 8 has a further winding 11 which is magnetically coupled to the first winding 9 via the iron core 12 of the transformer 8. With the two ends 13, 14 of the further winding 11, two switch pairs 15, 16 and a short-circuit switch 17 are connected.
  • the actuating unit 4 can be brought into four different switching states.
  • the first switching state in which the switch pair 15 is closed and the switches 16, 17 are open, the input voltage U E is applied to the further winding 11.
  • the winding direction of the windings 9, 11 defined by the points 19, 20 is selected such that the voltage ⁇ U 1 , which in this first switching state is caused by the further winding 11 in the first winding 9 is induced, added to the input voltage U E.
  • the voltage is thus obtained between the output connections 5, 6 of the control unit
  • the voltage ⁇ U 2 induced in the second switching state is always somewhat smaller than the voltage ⁇ U 1 induced in the first switching state.
  • the increase in output voltage U A that can be achieved with the circuit arrangement according to FIG. 1 in the first switching state compared to the input voltage U E can be achieved with very good accuracy, similar to that which can be achieved in the second switching state
  • a third switching state of the actuating unit 4 the two switch pairs 15, 16 are open and the short-circuit switch 17 is closed.
  • the circuit, thus short-circuited, further winding 11 has a very small resistance, which, due to the fact that the turns ratio w 1 / ww is significantly smaller than 1, appears to be correspondingly transformed down on the side of the first winding 9.
  • the first winding 9 in this switching state represents an extremely small resistor for the load current, to which practically no voltage drops, so that the following applies with very good approximation:
  • the two pairs of switches 15 and 16 and the short-circuit switch are actuated by a switch control 23 which, via lines 25, 26 and 27, switches 15, 16 and 17, which can be formed, for example, by triacs. controlled in the required manner. It is ensured that the switches 15, 16 and 17 are never closed at the same time and, on the other hand, the periods in which the switch is made from one switching state to another are kept as short as possible. In the event of a transition from the first or second switching state to the third or vice versa, the switch pairs 15 or 16 must be opened shortly before the time or closed shortly after the time in which the short-circuit switch 17 is closed or opened.
  • the transformer 8 in the exemplary embodiment shown in FIG. 1 has its own short-circuit winding 28, which with the aid of of a switch 29, which is parallel to it, can be short-circuited.
  • This switch 29 is controlled by the switch controller 23 via a line 30 and is only closed for those periods during which the two switch pairs 15, 16 are temporarily open simultaneously when switching from one switching state to the other.
  • FIG. 2 shows a transformer circuit with an actuating unit 34, the structure of which differs from that of the actuating unit 4.
  • the function of the Actuating unit 34 is basically the same as that of actuating unit 4.
  • the actuating unit 34 in turn comprises a transformer 8, the first winding 9 of which is connected between the input terminal 2 and the output terminal 5, while the other input terminal 3 is directly electrically connected to the other output terminal 6 via the terminal connecting conductor 10.
  • the transformer 8 has two further windings 35, 36, one end of which, as an additional winding 35, is firmly connected at one end to the end of the first winding 9 in a galvanically conductive manner, which is directly electrically connected to the input terminal 2, while the other end of the adding winding 35 can be connected to or disconnected from the connecting connecting conductor 10 with the aid of a switch 37.
  • the other of the two further windings is fixed as a subtracting further winding 36 with one end and is directly galvanically conductively connected to the end of the first winding 9, which is directly galvanically conductively connected to the output terminal 5 of the actuating unit 34, while the other end of the subtracting another winding 36 can be connected or disconnected from the connecting connecting conductor 10 with the aid of a switch 38.
  • the sense of winding of the three windings 9, 35 and 36, which are magnetically coupled to one another via the core 12, is identified by points 19, 20 and 21.
  • a short-circuit switch 31, 32 is arranged parallel to each of the two further windings 35, 36, which short-circuits the associated further winding 35 or 36 in the closed state.
  • the two short-circuit switches 31, 32 are controlled via a line 33 so that they are always open or closed at the same time.
  • the switches 31, 32, 37 and 38 are controlled so that either only the switch 37 or only the switch 38 or only the switches 31, 32 are closed.
  • the actuating unit 34 can thus be brought into the same three switching states as described above for the actuating unit 4.
  • the actuator can 34 by opening all the switches 31, 32 are brought into a corresponding fourth switching state, 37 and 38, the non-operating state e-called "normal" B is used, but in the case of a load short-circuit for limiting the load-short-circuit current are used can .
  • one switch is less required in the exemplary embodiment according to FIG. 2 than in the exemplary embodiment in FIG. 1, whereby the disadvantage of a second further winding is largely compensated for.
  • U E + .DELTA.U 1 and U A2 UE - - .DELTA.U 2 also not the embodiment shown in Figure 2 so that here so the two output voltages U A1 offers the possibility ⁇ U 1 independently within certain limits of ⁇ U 2 to choose more necessarily must be symmetrical to the input voltage U E.
  • a switch controller 23 which outputs the control signals for the switches 37, 38 and 31, 32 via the lines 25, 26, 27.
  • the lines 25, 26, 27 are not connected directly to the switches 37, 38, 31, 32, but are each connected to an input of an AND gate 39, 40, 41, the other inputs of which are controlled by sensor units 42.
  • Each of the sensor units 42 has two input connections, with the aid of which it queries the voltage drop across the associated switch 37, 38 or 31.
  • the purpose of these sensor units 42 and the AND gates 39, 40, 41 is to ensure that each of the two switches 37, 38 or the two switches 31, 32 can only be closed by a corresponding signal from the switch control 23 if the other switches have been opened beforehand.
  • the switch 37 of the actuating unit 34 If, for example, as shown in FIG. 2, the switch 37 of the actuating unit 34 is closed, then no voltage drops across this switch 37. Therefore, the associated sensor unit 42 generates a logic O signal at its output, which blocks the AND gates 40, 41 and prevents a closing signal from switch controller 23 from reaching switches 38 and 31, 32. These switches can therefore only be closed when the switch 37 has been opened, which is indicated by the sensor unit 42 by supplying the AND gates 40, 41 with a logic 1. The same applies in reverse naturally also for querying the closed state of the switches 38 and 31, 32 by the associated sensor units 42 and a corresponding blocking or release of the AND gate 39.
  • triacs are used as switches 37, 38, 31, 32, these can of course not be controlled directly by the AND gates 39, 40, 41, but there is one between the output of these AND gates and the gate electrode of the triacs of the usual triac drive circuits is provided, which is omitted in Fig. 2 for the sake of clarity.
  • the sensor circuits 42 are described in more detail below with reference to FIG. 3.
  • the previously closed switch 37 or 38 must be opened and the previously opened switch 38 or 37 must be closed a short time later will.
  • the output voltage U A of the actuating unit 34 should change from the old to the new amplitude value as quickly as possible and without the occurrence of additional voltage peaks or voltage dips. To achieve this, it is expedient to open the previously closed switch 37 or 38 when the current flowing through the associated winding 35 or 36 has a zero crossing.
  • a triac is used as switch 37 or 38, this results in the opening of the switch at the right time, that is to say automatically when the current crosses zero by preventing re-ignition in the other direction after the triac has self-extinguished when the current crosses zero.
  • a previously opened switch 38 or 37 is preferably closed at such phase angles of the magnetic flux passing through the winding 9, in which the change in this magnetic flux caused by the closing of the switch 38 or 37 is as small as possible.
  • the phase angle of the magnetic flux depends on the load current, so that it cannot be given an exact value, but only a range. For the switch 37, this area is in the vicinity of the zero crossing of the magnetic flux, while for the switch 38 it is in the vicinity of the maximum of the absolute value of this magnetic flux.
  • the transformer 8 has a fourth winding, which serves as a sensor winding 43.
  • a voltage is induced in this sensor winding which has a constant phase shift with respect to the magnetic flux in the winding 9 which is independent of the load. This phase shift is constantly equal to 90 °, so that the switch 37 must always be closed in the area of the absolute maximum of this voltage and the switch 38 in the area of a zero crossing of this voltage. The information required for this is supplied to the switch control 23 from the winding 43 via the lines 44.
  • FIG. 3 shows only the two connecting lines to the actuating unit 34, which supply the voltage dropping at the associated switch, for example at the switch 37, from above, and the line which, at the bottom, supplies the control signal for the two AND gates of the other switches, for the AND gates 40, 41 of the switches 38 and 31, 32.
  • the AC voltage dropping across the switch 37 in the open state is rectified with the aid of a rectifier 46, the DC voltage outputs of which are connected to one another via a resistor 47 and a photodiode 48 of an optocoupler 49.
  • a phototransistor 50 of the optocoupler 49 is connected on the one hand via a resistor 51 to a supply voltage V and on the other hand directly to ground.
  • the voltage which can be tapped off from the ground between the collector of the phototransistor 50 and the resistor 51 is fed via a line 52 to an inverter 53, the output of which is connected to the output line leading to the AND gates 40, 41 which carry the closing signals can come, release or block from the switch control 23 via the lines 26, 27.
  • the rectifier 46 If the switch 37 is open, the rectifier 46 generates a direct voltage from the alternating voltage then dropping at the switch 37, which causes the diode 48 of the optocoupler 49 to light up.
  • the "low” signal then emitted by the phototransistor 50 is inverted by the inverter 53 into a “high” signal, which the AND gates 40, 41 enable.
  • FIG. 4 shows two actuating units 54, 54 ', which have an identical structure, which differs from the structure of the actuating unit 34 shown in FIG. 2 only in that the two short-circuit switches 31, 32 are omitted.
  • the AND gate 41 from FIG. 2, which controls these two switches 31, 32, and the one of the three sensor units 42, which queries the switching state of the switches 31, 32 are also omitted.
  • the two remaining AND gates 39, 40 accordingly only require two instead of three signal inputs. Otherwise, the basic structure of the actuating units 54, 54 'is the same as that of the actuating unit 34 and the corresponding parts are provided with the same reference numerals.
  • the two actuating units 54, 54 ' are connected in series with one another, ie the output voltage U A appearing at the output connections 5, 6 of the actuating unit 54 is fed directly to the input connections 2', 3 'of the actuating unit 54' as the input voltage U E ' .
  • the input connections 2, 3 of the control unit 54 are supplied with the supply voltage U v output by the voltage source 1 as input voltage and the output voltage output at the output connections 5 ', 6' of the control unit 54 'is applied to the load 7 as the load voltage U L , the first two windings 9, 9 'of the two transformers 8, 8' seen from the voltage source 1 with the load 7 in series.
  • the two actuating units 54, 54 'have no short-circuit switches means that each of them can only be brought into three of the four switching states defined above. If the fourth switching state, in which the switches 37, 38, 37 ', 38' are all open, is left aside only for the emergency of a load short circuit, then only operating switching states remain for each of the two actuating units 54, 54 ' the first two switching states in which they can be brought independently of each other.
  • each of the two control units 54, 54 ' can only input the input voltage U E or U E to them with a changed amplitude, ie either with an additive or a subtractive voltage change + ⁇ U 1 or - ⁇ U 2 or Pass on + ⁇ U 1 'or - ⁇ U 2 '. Since the turn ratios of the further windings 35, 36 and 35 ', 36' to the associated first winding 9, 9 'can in principle be determined independently of one another, a total of four different load voltages U L can be generated for a given supply voltage Uv.
  • these turns ratios to form a pair of actuators are set so that the percentage increase in the output voltage U AP of the pair compared to the input voltage U EP of the pair, which results when the switches 37, 37 'are closed, is equal to the percentage decrease in the output voltage U AP is compared to the input voltage U EP , which results when the switches 38, 38 'are closed, and that the output voltage U AP is, with great accuracy, equal to the input voltage UEP when the switches 37 and 38' are closed, that is to say the front, ie Actuator 54 located closer to voltage source 1 is in the first switching state and rear actuating unit 54 'is in the second switching state.
  • the pair of actuating units thus has four combinations of switching states, three of which correspond to the three switching states of the individual actuating units 4 and 34 described above:
  • the fourth switching state combination remains unused.
  • the function of such a pair of actuating units 54, 54 ' is practically the same as the function of an individual actuating unit 4 or 34.
  • a pair of actuators offers the advantage that, given the size of the voltage to be applied and thus the power to be switched, each of the two actuators can only handle half of this switching power must and can therefore be dimensioned accordingly smaller.
  • the two transformers 8, 8 'of the actuating unit pair 54, 54' together are only slightly larger and heavier than the one transformer 8 of an actuating unit 4 and 34, respectively, with the same switching capacity.
  • a single actuating unit 54 or 54 ' is in any case considerably smaller and lighter than an actuating unit 4 or 34, ie there are smaller and lighter subunits, which has considerable structural advantages in arrangements in which a large number of such actuating units or actuating unit pairs are connected in series brings. Transport is also much easier if you can break down such a system into several smaller and lighter sub-units.
  • Two smaller units also have the advantage that they lead to smaller losses than a single unit with the same switching capacity.
  • such a pair of actuating units can also be constructed from two actuating units 174, 174 ', as will be described below with reference to FIG. 9.
  • FIG. 5 shows a transformer circuit which serves as a single-phase voltage constant for the voltage U L supplied to the load 7.
  • a set value S L is specified for the amplitude of the alternating voltage supplied to the load 7, which is set to 100% below, and from which the voltage actually applied to the load 7 may deviate by a maximum of + ⁇ % .
  • the stressessspan- supplied from the AC power source 1 is a representation nu ng Uv in its amplitude by A +% of nominal value Vnom U.
  • the setpoint S L the load voltage U L is equal to the nominal value U Vnenn of the supply voltage U v or different from this nominal value.
  • the transformer circuit according to the invention enables the load voltage U L to be regulated to a desired value S L , which is, for example, at or near the limit of the intended control range.
  • S L a desired value
  • this is only useful if deviations in the supply voltage can only occur in one direction. If, for example, the supply voltage is generated from a battery arrangement with the aid of an inverter, this requirement is met without further ado, since the direct battery voltage and thus also the amplitude of the alternating voltage generated therefrom only prolonged operation with progressive discharge of the battery arrangement, but not can increase.
  • a transformer circuit according to the invention is provided between the voltage source 1 and the load 7, which consists of three stages 55, 56, 57 connected in series with one another, each of which is operated either by an actuating unit 4, 34, 144 or 174 according to FIG. 1 , 2, 8 or 9 or can be formed by a pair of actuating units 54, 54 'according to FIG. 4 or by a pair of actuating units which is constructed from two actuating units 174, 174' according to FIG. 9. Steps 55, 56, 57 are controlled with the aid of a switch control 23, which is connected to each step 55, 56, 57 via a pair of lines 61, 62 connected is.
  • an actuating unit 34 an actuating unit 144, an actuating unit 174, an actuating unit pair 54, 54 'or an actuating unit pair 174, 174'
  • these line pairs symbolize , lines 25, 26, 27 and 30 (see FIG. 1), lines 25, 26, 27 and 44 (see FIG. 2), lines 158, 159, 160, 161 and 30 (see FIG 8), lines 163, 164, 165 and 30 (see FIG. 9), lines 26, 27, 44, 26 ', 27' and 44 '(see FIG. 4) or twice lines 163, 164, 165 and 30 (see Fig. 9).
  • the switch control 23 issues the switching commands to the switches of the stages 55, 56, 57 via the lines 61 and receives the information generated by the sensor windings 43 about the phase position of the magnetic flux in the first windings 9 of the transformers 8 and thus via the lines 62 the favorable closing times and periods for the switches. Furthermore, a first comparator 63 is provided, which receives a reference voltage U ref1 at one of its two inputs, which represents the setpoint S L for the load voltage U L. The other of its two inputs is supplied with the output signal of a first sensor 64, which measures the load voltage U L. Upper line 65, the comparator 63 outputs a differential signal to the switch controller 23, which indicates whether and how far the load voltage U L L S deviates from the setpoint.
  • the switch controller 23 changes the switching states of stages 55, 56, 57, which then impress a new amplitude change on the supply voltage U V and thus the load voltage U L within the permissible control range Hold ⁇ ⁇ %.
  • a second comparator 66 is provided which r- a nominal value Vnom the U Ve supply voltage Uv corresponding reference voltage U ref2 to the output signal of a second probe 67 compares precisely of this supply voltage U v is measured.
  • the differential signal emitted by the second comparator 66 is likewise fed via line 68 to the switch control 23, which can thus operate not only in the control mode but also in the control mode or in a combination of both.
  • the switch controller 23 preferably comprises a microprocessor for processing the information coming in via the lines 62, 68 and 65 and for converting this information into corresponding switching commands.
  • the stages 55, 56, 57 are constructed in such a way that each stage increases the input voltage supplied to it in a first switching state or in a first switching state combination by a predetermined percentage, in a second switching state or in a second switching state -Combination reduced by approximately the same percentage rate and passed on unchanged in a third switching state or in a third switching state combination.
  • switching state combinations also referred to simply as the first, second or third switching state.
  • the specified percentages by which the individual stages can change the input voltage supplied in each case differ from stage to stage and are preferably approximately in relation to one another in the form of integer powers of three.
  • the last stage 57 which is closest to the load 7, can change the input voltage supplied to it, for example, by + A% or pass it on almost unchanged.
  • the middle stage 56 can change the input voltage supplied to it by approx. + 3A% or pass it on almost unchanged and the foremost stage 55 closest to the voltage source 1 can change the input voltage supplied to it by approx. + 9A% or pass it on almost unchanged.
  • each stage 55, 56, 57 by an adjusting unit pair 54, 54 'or 174, 174' shown in Table 3 again in greater detail for the case in which + A%% w + 1% is selected so that there is a possible amplitude change of approx. + 3% of the input voltage supplied to this pair for the actuator unit pair of the middle stage 56 and a possible amplitude change of approx. + 9% for the actuator unit pair of the foremost stage 55 results.
  • the additive winding of the actuating unit 54 or 174 can effect a change of + 4.5%, while the subtracting winding can bring about a change of - 4.9%, and the additive one or subtracting winding of the actuating unit 54 'or 174' can impress a change of + 4.4% or - 4.2% on the input voltage of this rear actuating unit 54 'or 174' of stage 55.
  • level 56 with values that are about 0.02% to 0.03% higher, as can be seen in Table 3 without any problems.
  • Table 4 Similar to Table 2 on the left, the twenty-seven switching state combinations are listed again, which can be achieved with a transformer circuit comprising three actuator unit pairs according to FIG. 5, if only three switching state combinations are used for each actuator unit pair.
  • Table 4 shows for each actuating unit 54, 54 'of the three actuating unit pairs whether the adding or subtracting winding is connected to the associated input or output voltage.
  • a “1” means that the relevant further winding is connected to the associated voltage
  • an "O" indicates that the winding can be opened by opening the relevant switch 37, 37 'or 38, 38' from the connecting connecting conductor 10 ( see Fig. 4) separately and therefore not connected to the input or output voltage.
  • the number combination 1001 for a pair of actuating units thus means that in the front actuating unit, ie closer to the voltage source 1, the additive winding is switched on and the subtracting winding is switched off, while in the rear actuating unit arranged closer to the load 7, the additive winding switched off and the subtracting winding is switched on.
  • a pair of actuators identified in this way is therefore in the third switching state combination defined above, in which the effects of the front and rear actuators virtually cancel each other out, so that the input voltage appears at the output of the actuator pair with an almost unchanged amplitude.
  • the switch controller 23 selects this combination when the supply voltage U V has dropped significantly compared to the setpoint.
  • the supply voltage U V can have risen to 114.84% of the target value without the load voltage the upper limit exceeds 100.5% of the permissible range.
  • stages 55, 56, 57 are formed by a pair of actuating units comprising two actuating units 174, 174 'according to FIG. 9 or by individual actuating units 4, 34 and 144, respectively.
  • Fig. 6 shows a modification of the circuit arrangement according to the invention, as it can be used to control the voltage output by a three-phase network.
  • a transformer circuit 75, 76, 77 is provided for each of the three phase conductors R, S and T, each of which is constructed in the same way as the transformer circuit in FIG. 5. It therefore exists each of these three transformer circuits 75, 76, 77 from three stages 55, 56, 57 connected in series, each of which here consists of a pair of actuating units 54, 54 'and 174, 174' and can assume four different switching states.
  • the AC voltage on each of the three phase conductors R, S and T can thus be subjected to change amounts which are in a ratio of 1: 3: 9 to each other, or the AC input voltage can be passed on unchanged or the load current can be throttled.
  • each of the transformer circuits 75, 76, 77 is not only with its associated phase conductor R, S or T, but also with the zero -N conductor connected.
  • a three-phase network 80 is used here as the voltage source.
  • the voltage amplitudes supplied by the network 80 on the individual phase conductors R, S, T are continuously measured with the aid of a sensor arrangement 81, which supplies the three measurement signals to a comparator arrangement 82. There, the measurement signals are compared with a common reference value U ref . Alternatively, a separate reference value can also be specified for each phase conductor R, S and T.
  • the comparator 82 generates a separate difference signal for each of the three phase conductors R, S, T, which is fed to a switch controller 83.
  • This controls via the line groups 85, 86, 87, the switches of the stages 55, 56, 57 in each of the transformer circuits 75, 76, 77 in the manner as has been explained in detail above.
  • each control unit is connected to the switch control 83 via several lines, as shown in FIGS. 1, 2, 4, 8 and 9. For the sake of simplicity, however, these lines have only been shown in FIG. 6 as a single bidirectional line.
  • each transformer circuit 75, 76, 77 is formed by a phase conductor R K , S K or T K ' , the letter "K" indicating that an AC voltage with a constant amplitude is available on these phase conductors.
  • These voltages can either be applied together to a single load that requires a three-phase current, or different loads, each of which only has to be operated with a 1-phase alternating current.
  • the sensor arrangement 81 can also be designed in a multi-phase system in such a way that it measures the AC voltages supplied to the phase conductors R K , S K , T K of the loads.
  • the circuit arrangement according to the invention can also be used in multiphase systems which comprise fewer or more than three phases.
  • FIG. 7 shows a further embodiment of a transformer circuit according to the invention, which comprises only a single actuating unit 94.
  • a supply voltage U v which comes from a voltage source 1 is also supplied to the input connections 2, 3 of the actuating unit 94 as the input voltage U E.
  • An output voltage U A appears at the output connections 5, 6 and is supplied to a load 7 as a load voltage U L.
  • the actuating unit 94 comprises a transformer 8, the first winding 9 of which is connected between the input terminal 2 and the output terminal 5, while the other input terminal 3 is directly electrically conductively connected to the second output terminal 6 by means of the connecting connecting conductor 10.
  • the transformer 8 also has a further winding 11 which is magnetically coupled to the first winding 9 via the iron core 12 of the transformer 8.
  • the actuating unit 94 of the present exemplary embodiment can be brought not only into four but into thirty-four different switching states, so that it is possible to make a total of thirty-two different amplitude differences between the input voltage U E and the output voltage U A to produce the one control unit 94, to make the input voltage U E unchanged at the output connections 5, 6 available or to throttle the load current in the event of a short circuit on the load.
  • transformer circuit shown in FIG. 7 to be used as a voltage regulator and / or voltage constant similar to the transformer circuits in FIGS. 5 and 6.
  • FIG. 7 shows the use as a voltage regulator, in which the output voltage U A of the actuating unit 94, which here is equal to the load voltage U L, is in turn fed to a sensor arrangement 64 via lines 95, 96.
  • the sensor 64 transmits a measurement signal to a comparator 63, which compares this measurement signal with a reference voltage U ref , which corresponds to the target value S L of the load voltage U L.
  • the comparator 63 passes a difference signal representing the difference between the measurement signal and the reference voltage U ref to a switch controller 23, which controls a switch group 98 consisting of fourteen switches via lines 97 in order to bring the actuating unit 94 into the different switching states , as will be explained in more detail below.
  • the AC voltage source 100 is formed by an additional transformer arrangement 101, which in the present case Case consists of six winding sections 104 to 109 electrically connected in series, which are magnetically coupled to one another via a common transformer core 111.
  • the one end of the group consisting of the winding sections 104 to 109 series circuit is electrically directly conductively connected to one pole of the AC voltage source 1, is connected to the well, the input terminal 3 of the actuating unit 94, which via the terminal-Verbindun g s-conductor 10 directly electroplated is conductively connected to the output terminal 6 of the actuating unit 94.
  • the other end of the series circuit consisting of the winding sections 104 to 109 is connected via a line 114 to the second output connection 5 of the actuating unit 94.
  • the output voltage U A of the actuating unit 94 is present at the series connection of the winding sections 104 to 109.
  • the series connection of the winding sections 104 to 109 has seven taps 121 to 127, of which the taps 121 and 127 are connected to the two outer ends of the series connection, while the taps 122 to 126 are each led out between two adjacent winding sections.
  • Each of the taps 121 to 127 is connected to a pair of on / off switches from the switch group 98.
  • one switch of each pair of switches connects the associated tap to a line 129 which is connected to the lower end of the further winding 11 in FIG. 7.
  • the other switch of each pair in the closed state, connects the associated tap to a line 130 which connects to the other end of the further winding 11 in Connection is established.
  • the actuating unit can be brought into thirty-two different switching states, sixteen of which are used to additively impress the respectively induced voltages ⁇ U 1 to ⁇ U 31 and sixteen to negatively impress the respectively induced voltage ⁇ U 2 to 4U32 are provided.
  • the amplitude of each positively impressed voltage is equal to the amplitude of a corresponding negatively impressed voltage.
  • the number of turns of the winding sections 104 to 109 are matched to one another according to a code which is optimized so that on the one hand the smallest possible number of winding sections 104 to 109 and thus also taps 121 to 127 and switches 98 is needed, and that on the other hand, the maximum required control voltage U Smax can be tapped between the most distant taps 121 and 127.
  • the winding section 109 has a number of turns such that when the output voltage U A of the actuating unit 94 is applied to the series connection of all the winding sections 104 to 109, a tap voltage 1 of this winding section 109.
  • U Xmin can be tapped, which corresponds to the smallest required control voltage U Smin .
  • the number of turns of the other winding sections 104 to 108 are selected such that the following tap voltages are available between adjacent taps 121 to 126:
  • the optimized code is also characterized here in that 1 times the minimum tapping voltage U Xmin can be tapped at one winding section 109 at the end of the series connection and 2 times U Xmin at the winding section 104 at the other end is.
  • the line 114 is not firmly connected to the line 95 at point 140.
  • two push-pull switches can be arranged here, with the help of which the end of the line 114 which is remote from the series connection of the windings 104 to 109 via corresponding lines either with the line leading from the output connection 5 to the load 7 or with the line from the voltage source 1 to the input terminal 2 leading line can be connected. These switches are then also controlled by the switch controller 23 in order to apply either the input voltage U E or the output voltage U A of the actuating unit 94 to the series connection of the windings 104 to 109.
  • the former preferably takes place when a voltage .DELTA.U 1 ..., .DELTA.U 31 is to be induced in the first winding 9 by a corresponding control voltage U S1 '... U S31 applied to the further winding 11 additively impresses the input voltage U E.
  • the line 114 is preferably connected to the output voltage U A when a voltage ⁇ U 2 ... ⁇ U 32 is to be induced in the first winding 9, which is subtractively impressed on the input voltage U E.
  • FIG. 8 again shows a single actuating unit 144, which is constructed similarly to the actuating unit 4 from FIG. 1 and is connected in the same way to change the amplitude of an AC voltage between an AC voltage source 1 and a load 7.
  • the transformer has only a single further winding 11, which is magnetically coupled to the first winding 9 via the iron core 12 of the transformer 8.
  • Two switches 150, 152 and 151, 153 are connected to the two ends 13, 14 of the further winding 11.
  • switch 150 If the switch 150 is closed, it connects the end 13 of the further winding 11 to the input terminal 2, to which the one end of the first winding 9 is also connected. If the switch 151 is closed, it connects the other end 14 of the further winding 11 to the output terminal 5, to which the other end of the first winding 9 is connected.
  • the switch 152 If the switch 152 is closed, it connects the end 13 of the further winding 11 to a line 155, with which the switch 153 also connects the other end 14 of the further winding 11 in the closed state.
  • a circuit arrangement 157 is provided between the line 155 and the connecting connecting conductor 10, which can be a simple controllable off / on switch, but is preferably formed by a current limiting circuit, as will be explained in more detail below with reference to FIG. 10 .
  • the actuating unit 144 can be brought into four different switching states.
  • the first switching state in which the switches 150 and 153 are closed, the input voltage U E is applied to the further winding 11 and the current limiting circuit 157 lying in series therewith. Since the limit value to which the current limiting circuit 157 limits the current flowing through it is selected to be greater than the current which flows through the further winding 11 in this first switching state, the voltage drop across the current limiting circuit 157 is very small and it is practically the whole Input voltage U E at the further winding 11 as a control voltage.
  • the winding direction of the windings 9, 11 defined by the points 19, 20 is selected such that the voltage ⁇ U 1 , which is induced in this first switching state by the further winding 11 in the first winding 9, is added to the input voltage U E.
  • the voltage is thus obtained between the output connections 5, 6 of the control unit
  • the switches 150 and 153 are open and the switches 151 and 152 are closed, as a result of which the output voltage U A of the actuating unit is connected to the further winding 11 and the current limiting circuit 157 which is in series with it again 144 is laid. Since the current flowing through the further winding 11 in this second switching state is approximately equal to the current flowing through the further winding 11 in the first switching state, this current is also below that
  • ⁇ U 2 w 1 U E / (w w + w 1 ) applies to the induced voltage.
  • the voltage ⁇ U 2 induced in the second switching state is therefore somewhat smaller than the voltage ⁇ U 1 induced in the first switching state.
  • a third switching state of the actuating unit 144 at least the two switches 150 and 151 are closed, so that the further winding 11 with antiparallel winding direction to the first winding 9 and electrically parallel to this first winding 9 is at the same voltage as this.
  • the transformer 8 is therefore short-circuited and the currents flowing in the two antiparallel windings 9, 11 each try to build up a magnetic field; however, these fields face each other and almost cancel each other out.
  • the leakage inductance of the first winding 9 can be kept so low that the first winding 9 the load current flowing through it in this circuit state only opposes their very small ohmic resistance, whereby the voltage drop occurring at the first winding 9 is very small. This means that applies in this third switching state
  • the current limiting circuit 157 can be dispensed with, ie the conductor 155 can be connected directly to the connecting connecting conductor 10 in a galvanically conductive manner.
  • the switches 151, 152 must first be opened, and the switches 150 only when these switches are open with certainty , 153-can be closed.
  • the actuating unit 144 is first brought into the third switching state, which is done by closing the first switch 150. A short time later, the third switch 152 is then opened and the fourth switch 153 is then closed. The actuating unit remains in the third switching state since the first switch 150 and the second switch 151 are closed during this time. Short-circuiting of the two windings 9 and 11 by the further conductor 155 is avoided in that the two switches 152 and 153 are not closed at the same time.
  • the current limiting circuit 157 prevents the flow of an inadmissibly large short-circuit current from the connection 5 or connection 2 to the connection connecting conductor 10 via the simultaneously closed switches 151, 153 or the simultaneously closed switches 150, 152.
  • the switch 151 is then opened as the last step of the switching process, as a result of which the actuating unit changes from the third switching state to the first switching state.
  • the actuating unit 144 also briefly passes through the third switching state whenever it is intended to change from the first to the second or from the second to the first switching state. If the actuating unit 144 is to be kept in the third switching state for a longer period of time, the switches 152 and / or 153 are opened so that no more currents can flow from the input connection 2 or from the output connection 5 to the connection connecting conductor 10, and the power loss is thus further reduced .
  • a fourth switching state all four switches 150 to 153 are open, so that the circuit of the further winding 11 has a high resistance value, which provides a high resistance value even after transformation down on the side of the first winding 9. A voltage drop dependent on the size of the load current thus occurs at the first winding.
  • This throttling effect of the first winding 9 in the fourth switching state can be used to limit the power supplied to the load to a safe level at least until a short circuit occurs at the load until further switch-off measures have been taken.
  • the switches 150 to 153 are actuated by a switch control 23, which controls the switches via lines 158, 159, 160 and 161.
  • the switch controller 23 can obtain the information required for this from a comparator (not shown in FIG. 8), which compares the load voltage U L and / or the supply voltage U v with target values and, in the event of deviations, outputs corresponding differential signals, as described in detail above.
  • the transformer 8 of the actuating unit 144 comprises a short-circuit winding 28 which can be short-circuited with the aid of a switch 29 which is parallel to it.
  • This switch 29 is also controlled by the switch control 23 via a line 30. According to the invention, this only occurs when certain faults occur in the switches 150 to 153 or in the current limiting circuit 157, as will be explained in more detail below.
  • the current limiting circuit 157 in the actuating unit 144 can be omitted without the delays in the switching process mentioned above having to occur.
  • the two switches 152, 153 which are then directly connected again to the connecting connecting conductor 10, are each designed as a current limiting circuit, the limit value of which can be switched back and forth between the value zero and a value other than zero . If such a current limiting circuit is switched to the limit value zero, this corresponds to the open state of a switch. If, on the other hand, it is switched to the limit value other than zero, it only opposes the current flowing through it with a very small, constant resistance as long as this current remains significantly below the limit value. This limit becomes so chosen that it is greater than the current that must flow through the further winding 11 and the relevant switch 153 or 152 in the first or in the second switching state.
  • the switchover from the first to the second switching state or from the second to the first switching state takes place in such a way that the two previously open switches are closed simultaneously and a short time later the two switches which are open in the new switching state are opened simultaneously have to. If switches 150 and 151 are implemented with the help of triacs, this opening process must be used to wait until the next zero crossing of the current which flows through the relevant switch 150 or 151 before opening.
  • the actuating unit can be brought into the fourth switching state by opening all four switches 150 to 153 simultaneously.
  • FIG. 9 shows a transformer circuit with an actuating unit 174, the structure of which differs from that of the actuating unit 144, but which in principle has the same functions.
  • the actuating unit 174 in turn comprises a transformer 8, the first winding of which is connected between the input connection 2 and the output connection 5, while the other input connection 3 is connected via the on final connecting conductor 10 is directly electrically conductively connected to the other output terminal 6.
  • the transformer 8 here also has two further windings 35, 36, of which the one as an additional winding 35 is firmly connected at one end to the end of the first winding 9 in a galvanically conductive manner is directly electrically connected to the input terminal 2, while the other end of the adding winding 35 can be connected or disconnected from a line 185 by means of a switch 180, which in turn is connected to the connecting connecting conductor 10 via a current limiting circuit 157.
  • the other of the two windings is fixed as a subtracting further winding 36 with one end and is directly galvanically conductively connected to the end of the first winding 9, which is directly galvanically conductively connected to the output terminal 5 of the actuating unit 174, while the other end of the further subtracting Winding 36 can be connected or disconnected from line 185 by means of a switch 181.
  • the sense of winding of the three windings 9, 35 and 36, which are magnetically coupled to one another via the core 12, is identified by points 19, 20 and 21.
  • the limit value of the current limiting circuit 157 is selected to be greater than the currents which are generated in the first switching state by the adding winding 35 or in the second switching state by the subtracting one Winding 36 flow.
  • a current limiting circuit 157 is again provided here between the conductor 185 and the connecting connecting conductor 10 , which could in principle be replaced by a controllable on / off switch.
  • protection times would then have to be introduced and special verification circuits would have to be provided for switching from one switching state to the other, so that it can be excluded with absolute certainty that switches 180 and 181 are operated simultaneously be closed as long as the switch connecting lines 185 and 10 is closed.
  • a current limiting circuit is therefore preferably used again as circuit arrangement 157, which automatically and without time delay prevents a further increase in the current flowing through it if this current threatens to exceed a predetermined limit value.
  • the actuating unit 174 can also be brought into a fourth switching state, as shown in FIG. 9.
  • this switching state the two switches 180 and 181 are opened at the same time, as a result of which a strong throttling action of the first winding 9 occurs again, which can be used to limit the short-circuit current in the event of a load short circuit.
  • Switching from the first to the second or from the second to the first switching state also takes place here in such a way that the one of the two switches 180, 181 that was previously open is closed, and only then is the switch closed until then opened.
  • the actuating unit 174 therefore also briefly passes through the third switching state with each transition from the first to the second or from the second to the first switching state.
  • the current limiting circuit 157 is controlled via two lines 163 by the switch controller 23 so that its limit value is significantly smaller Value, preferably takes the value zero.
  • the current limiting circuit 157 then acts. an open switch and practically only the very small short-circuit current flows, which is driven by the small voltage drop across the first winding 9 in the two further windings 35, 36.
  • the switches 180, 181 are controlled by the switch controller 23 via the lines 164, 165.
  • the transformer 8 of the actuating unit 174 also has a short-circuit winding 28 which can be short-circuited via a switch 29 which is controlled by the switch controller 23 via a line 30.
  • a fuse 167 can also be provided in the actuating unit 144 shown in FIG. 8, which is connected in series with the current limiting circuit 157.
  • FIG. 10 shows a current limiting circuit 157, as can be used in the actuating units 144, 174 in FIGS. 8 and 9.
  • This current limiting circuit has two current connections 187, 188, one of which is connected directly to line 155 or line 185 and the other to the connecting connecting conductor 10 in a directly electrically conductive manner.
  • a series circuit is arranged between the two current connections 187, 188 and consists of the source-drain path of a first V-MOS transistor 190, two resistors 192, 193 and the source-drain path of a second V-MOS transistor 191 .
  • Parallel to this series connection are between the two power connections 187, 188 two diodes 198, 199 connected in series with one another, whose forward directions are opposite to each other.
  • the connection point 196 of the two diodes 198, 199 is electrically connected to the connection point 195 of the two resistors 192, 193.
  • each of the two transistors 190, 191 has a diode characteristic, i.e. its blocking effect can only develop in one direction
  • the two transistors 190, 191 are arranged so that their forward directions are parallel to the forward direction of the diodes 198 and 199 lying in the parallel branch and thus opposite to each other.
  • an alternating current can also be limited in the required manner with the aid of this current limiting circuit 157.
  • the diodes 198, 199 are selected so that the voltage drop across them when the rated current flows is smaller than the corresponding voltage drop across the parallel V-MOS transistor 190 and 191, respectively. Since each diode 198 and 199 is not only the one parallel to it V-MOS transistor 190 or 191 but also bypasses its associated series resistor 192 or 193, the half-waves of the alternating current to be limited either flow via diode 198 and further via resistor 193 and V-MOS transistor 191 or via the diode 199 and further via the resistor 192 and the V-MOS transistor 190.
  • the alternating current in each half-wave can be limited as required by one of the two V-MOS transistors 190 and 191; on the other hand it is avoided that the half-waves also the second Resistor and the second V-MOS transistor must flow through, which are only necessary for limiting the half-waves with the other sign.
  • the power loss occurring in the current limiting circuit 157 can thus be kept particularly small.
  • the gate voltage for the two transistors 190, 191 supplied from the switch controller 23 via the two lines 163 is applied between the connection point 195 of the two resistors 192, 193 and the two gate connections of the transistors 190, 191.
  • the size of this gate voltage is selected so that the current flowing from one of the two connections 187, 188 to the respective other connection cannot exceed a predetermined limit value.
  • the gate voltage supplied via the lines 163 is chosen to be so low that it is below the threshold voltage U TH of the V- MOS transistors 190, 191, which thus practically no longer allow current to flow through their source / drain path.
  • switches 150 to 153 or 180 and 181 triacs can be used as switches. However, this means that these switches can only be opened when the current flowing through them passes through a zero crossing. It has already been pointed out that according to the invention, switches which are initially open until then are closed when changing from one switching state to the other. Then Both the actuating unit 144 and the actuating unit 174 are each in their third switching state. The respective short-circuit current then flows through the switches 150, 151 or 152, 153 or 180, 181 and it can only be switched to the subsequent first or second switching state when this short-circuit current passes through a zero crossing.
  • the further winding 11 or one of the two further windings 35, 36 is connected to its control voltage U E or U A , which as a rule attempts to force the flow of a current against the current flowing up to that point Short-circuit current is out of phase, that is, at the point in time at which the respective switch is opened, has no zero crossing.
  • FIG. 11 shows a diagram of the curve of an oscillation period of the input voltage U E , the short-circuit current I K flowing in the third switching state, the current 1 1 flowing in the first switching state and the current 1 2 flowing in the second switching state.
  • the amplitude of the short-circuit current I K is shown greatly enlarged for the sake of clarity.
  • switch 151 must be opened in the embodiment according to FIG. 8 and switch 181 in the embodiment according to FIG. 9. Since these switches are traversed by the short-circuit current I K , if they are implemented with the aid of triacs, they can only be opened at the time t 4 at which the short-circuit current I K passes through a zero crossing. It can be seen from FIG.
  • the compensation current I G is added to the current driven by the input voltage U, through the further winding 11 or 35. Since the transformer 8 is dimensioned so that the current which normally flows through a further winding connected to its control voltage is just below of the saturation limit, the transformer is driven into saturation by this compensation current I G. This has the consequence that there is a voltage drop in the switching process just described, the leads to the fact that the transition from the old to the new voltage amplitude is not completely smooth, but that voltage peaks are impressed on the first half-wave of the output voltage U following the switching operation.
  • switches 150 to 153 and 180, 181 also be constructed with V-MOS transistors instead of triacs, two of which are again connected in series with opposite polarity. These transistors have the advantage that the switch they form can be opened regardless of the size of the current flowing through them. It is therefore no longer necessary to wait for the next zero crossing of the short-circuit current I K , but the transition from the third to the first or second switching state can take place at a much more favorable time.
  • the optimal switching times would be the times t 2 or t 3 0 because in them the short-circuit current I K which flows in the other windings in question before the switching is equal to the current which after the switching process in the each additional winding should flow.
  • the time intervals ⁇ 1 and ⁇ 2 which have the replacement times t 2 'and t 3 ' from the nearest zero crossing of the input voltage U E , are load-dependent, they cannot be stored once and for all in the switch control 23. Instead, they are measured whenever the actuator 144 or 174 is in the first or second switching state, and the measured values are stored. If the next switch is to be made from the third switching state to the first or second switching state, the switching time t 2 'can be started on the basis of the time that has elapsed since the zero crossing t 1 of the input voltage U E , which is to be followed by the switching process. or the switching time t 3 'can be easily specified.
  • a control unit which is equipped with V-MOS transistor switches and a current limiting circuit 157 and which applies a voltage change + AU to its input voltage in the first switching state and causes a voltage change of - ⁇ U in the second switching state, from the first to the second switching state or reversed, the total voltage change 2 ⁇ U that occurs can be carried out in two steps; the first step in which the output voltage is changed by ( ⁇ U) takes place immediately ie simultaneously with the generation of the switchover signal. This is done in that the control unit is switched to the third switching state by closing one or more switches that were open until then. The second half of the required change is then accomplished within a period of time, which in the worst case is equal to half an oscillation period of the input voltage U E. Assuming that U E has an oscillation frequency of 50 Hz, the overall change can be accomplished within a maximum of 10 ms. Then the output voltage U A has a stable new value.
  • an actuating unit is to be switched to the first or second switching state after it has been in the third switching state for a long time. Since only one or two switches have to be opened during such a transition, after the changeover signal has been generated it is only necessary to wait until the next favorable switching time t 2 'or t 3 ' occurs. Since each of these points in time is available twice per AC voltage period, a time period corresponding to the length of a half cycle of the AC voltage must therefore be waited in the worst case before switching can take place. Although the change in the output voltage takes place in a single step, the magnitude of this change is only half the size of the total change which is made during the transition from the first to the second or from the second to the first switching state.
  • a particularly quick and precise switchover occurs when two of the actuating units 174 described above are connected in series to form a pair of actuating units.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Ac-Ac Conversion (AREA)
  • Control Of Electrical Variables (AREA)
EP85108921A 1984-07-24 1985-07-16 Circuit transformateur Expired - Lifetime EP0169488B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85108921T ATE68611T1 (de) 1984-07-24 1985-07-16 Transformatorschaltung.

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
DE3427291 1984-07-24
DE3427291 1984-07-24
DE3502889 1985-01-29
DE19853502889 DE3502889A1 (de) 1984-07-24 1985-01-29 Transformatorschaltung
DE3511182 1985-03-27
DE19853511182 DE3511182A1 (de) 1985-03-27 1985-03-27 Transformatorschaltung

Publications (3)

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EP0169488A2 true EP0169488A2 (fr) 1986-01-29
EP0169488A3 EP0169488A3 (en) 1987-08-19
EP0169488B1 EP0169488B1 (fr) 1991-10-16

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EP85108921A Expired - Lifetime EP0169488B1 (fr) 1984-07-24 1985-07-16 Circuit transformateur

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EP (1) EP0169488B1 (fr)
DE (1) DE3584401D1 (fr)

Cited By (2)

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Publication number Priority date Publication date Assignee Title
GB2198561A (en) * 1986-11-26 1988-06-15 Toshiba Kk Electric converting circuit with control through photocoupler
WO2015015216A1 (fr) * 2013-08-01 2015-02-05 Southern Fox Investments Limited Appareil et procédé de régulation de tension électrique

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KR930010265B1 (ko) * 1991-05-14 1993-10-16 삼성전자 주식회사 전자렌지의 구동회로
DE4431021C1 (de) * 1994-08-31 1995-10-19 Siemens Ag Ersatzschaltung für mehrere Funktionseinheiten
JP2561055B2 (ja) * 1994-11-18 1996-12-04 インターナショナル・ビジネス・マシーンズ・コーポレイション 情報処理装置及びその制御方法
US6351106B1 (en) * 2000-09-29 2002-02-26 Silicon Power Corporation Static voltage regulator and controller
US20090283824A1 (en) * 2007-10-30 2009-11-19 Northrop Grumman Systems Corporation Cool impact-ionization transistor and method for making same
RU2377630C1 (ru) * 2008-09-16 2009-12-27 Лев Залманович Фейгин Стабилизатор переменного напряжения с элементами защиты и резервирования (варианты)
WO2010091260A2 (fr) * 2009-02-06 2010-08-12 Abb Research Ltd. Transformateur de distribution hybride doté de capacités éléctriques en c.a. et en c.c.
KR20110120967A (ko) * 2009-02-27 2011-11-04 에이비비 리써치 리미티드 통합된 전압원 변환기를 구비한 하이브리드 배전 변압기
ES2679821T3 (es) * 2011-07-18 2018-08-31 Abb Schweiz Ag Transformador seco
CN112994549A (zh) * 2021-02-25 2021-06-18 上海交大海洋水下工程科学研究院有限公司 一种全海深rov动力电源的稳定装置、方法及介质
CN113258146B (zh) * 2021-03-29 2022-12-30 华为数字能源技术有限公司 一种电池系统、驱动系统及储能集装箱

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US3621374A (en) * 1970-04-16 1971-11-16 Gen Electric Voltage regulator with zero current static switching between taps for a regulator transformer
US3621375A (en) * 1970-04-16 1971-11-16 Gen Electric Voltage regulator with zero current static switching between tapped portions of the primary of a regulator transformer
DE2233020A1 (de) * 1971-07-06 1973-01-25 Edward Cooper Netz-wechselspannungsregler mit mehrfachumschaltungen ihrer anzapfungen der transformator-primaerwicklung
IT1010601B (it) * 1974-03-11 1977-01-20 Legnaioli L Macchina elettrica per variare il rapporto di trasformazione di una tensione con l ausilio di commuta tori
GB1476699A (en) * 1974-12-24 1977-06-16 Matsushita Electric Industrial Co Ltd Power supply system
US3970918A (en) * 1975-01-13 1976-07-20 Edward Cooper High speed, step-switching AC line voltage regulator with half-cycle step response
US4178539A (en) * 1978-08-03 1979-12-11 The Superior Electric Company Stepping AC line voltage regulator
GB2043971B (en) * 1979-03-13 1983-04-07 Koffler R Voltage regulators

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2198561A (en) * 1986-11-26 1988-06-15 Toshiba Kk Electric converting circuit with control through photocoupler
US4825351A (en) * 1986-11-26 1989-04-25 Kabushiki Kaisha Toshiba AC-DC converting apparatus having power factor improving circuit utilizing a photocoupler
GB2198561B (en) * 1986-11-26 1991-01-16 Toshiba Kk Ac-dc converting apparatus having power factor improving circuit
WO2015015216A1 (fr) * 2013-08-01 2015-02-05 Southern Fox Investments Limited Appareil et procédé de régulation de tension électrique

Also Published As

Publication number Publication date
EP0169488B1 (fr) 1991-10-16
US4774451A (en) 1988-09-27
EP0169488A3 (en) 1987-08-19
DE3584401D1 (de) 1991-11-21

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